Adding custom styles to odd/even rows in a GWT table

For the sake of better UI we decided to implement a table like gmail one that has differnt colors for even/odd rows. This seems to be quite a simple task, but I had to try several approaches before I managed to implement it.

1. Use custom RowFormatter 

RowFormatter interface defines a getElement method which is supposed to be called for every row. I believed that if you override it you can attach special style to a row object based on it's number.

Wrong guess =)

The specific table implementation - FixedWidthGrid - I was using from the gwt incubator project is using some custom/native logic inside prepareCell method so it doesn't call the getElement method =(

2. Directly override prepareCell method - doesn't seem correct, cuz would be called much more often then you need it

3. Finally I got the idea that I'm not able to find any OO way of introducing this functionality and went with a brute force approach: implement a method that applies some special formatting to all the rows and call it every time the table content is updated. 

Now I faced a new problem: there is no explicit "onContentUpdate" callback method I could use.

The only way my application now allows the content to be updated is by sorting it, so I implemented an appropriate callback. Here is the final source code packed into a class:

    public static class StripedTable extends FixedWidthGrid {
        private static final String EVEN_STYLE = "even_row";
        private static final String ODD_STYLE = "odd_row";

        public StripedTable() {
            super();
            addSortableColumnsListener(new SortableColumnsListener() {
                public void onColumnSorted(TableModel.ColumnSortList sortList) {
                    applyStripes();
                }
            });            
        }

        public StripedTable(int rows, int columns) {
            this();
            resize(rows, columns);
        }

        private void applyStripes() {
            for (int i = 0; i < getRowCount(); i++) {
                this.getRowFormatter().setStyleName(i, getRowStyle(i));
            }
        }

        private static String getRowStyle(int row) {
            return row % 2 == 0 ? EVEN_STYLE : ODD_STYLE;
        }
    }